This invention relates generally to a tuning device and more specifically to a tuning device having a pinion gear which is rotated by a worm to vary the tension in a string of a musical instrument.
There are many known tuning devices of the worm and pinion type for varying the tension in the string of a musical instrument. Some of these known tuning devices are disclosed in U.S. Pat. Nos. 3,564,573 and 2,356,766. The desirability of eliminating backlash between the worm and pinion gear of tuning devices has been recognized. Although backlash could be eliminated by merely providing extremely tight meshing engagement between the worm and pinion gear, this is unsatisfactory since it results in a tendency for the gears to jam and is detrimental to sensitivity of tuning. On the other hand if the worm and pinion gear are not disposed in a sufficiently tight meshing engagement, excessive backlash will be present and will impede the tuning of the strings of the instrument. Although the desired meshing relationship between the worm and pinion gear could be obtained by very accurate machining of the gears and their mountings, the cost of this machining is excessive and is therefore not commercially practical. Difficulty has also been encountered with prior art tensioning devices due to a lack of proper alignment and/or support of either or both of the gears.